Thursday, March 6, 2014

Presenter

The basic design of optical microscopes remains unchanged since Hooke and van Leeuwenhoek peered through them four centuries ago; today's light microscopes simply project an image of a slice through a sample onto either our eyes or a camera. However, by engineering a microscope's point spread function (PSF), or its impulse response to a point source, we can encode much more information into these images. In this talk, I highlight the double-helix (DH) microscope, an imaging system that bends the light emitted from point objects into a double-helix shape via a phase mask placed at a conventional microscope's pupil plane. I show that when utilized in concert with single-molecule photoswitching techniques like (F)PALM and STORM, the DH microscope routinely images 3D structures within living cells with resolution beyond the diffraction limit. I also demonstrate a polarization-sensitive DH microscope that measures simultaneously the 3D position and orientation of fixed single molecules, thus proving the nanoscale accuracy of this imaging technique. PSF engineering creates microscopes specifically tailored for decoding the complex nanoscale machinery at work within living cells. Matthew D. Lew is a PhD candidate in Electrical Engineering, a 3Com Corporation Stanford Graduate Fellow, and a National Science Foundation Graduate Research Fellow at Stanford University.